lat.cpp

This is a GPS communication source code to interrupt the NMEA code though serial port. Very good

#include "nmea0183.h"
#pragma hdrstop

/*
** Author: Samuel R. Blackburn
** Internet: [e-mail]
**
** You can use it any way you like as long as you don't try to sell it.
**
** Copyright, 1997, Samuel R. Blackburn
**
** $Workfile: lat.cpp $
** $Revision: 6 $
** $Modtime: 10/13/98 6:56a $
*/

#ifdef _DEBUG
#undef THIS_FILE
static char BASED_CODE THIS_FILE[] = __FILE__;
#define new DEBUG_NEW
#endif

LATITUDE::LATITUDE()
{
   Empty();
}

LATITUDE::~LATITUDE()
{
   Empty();
}

void LATITUDE::Empty( void )
{
   Latitude = 0.0;
   Northing = NS_Unknown;
}

BOOL LATITUDE::IsDataValid( void )
{
   if ( Northing != North && Northing != South )
   {
      return( FALSE );
   }

   return( TRUE );
}

void LATITUDE::Parse( int position_field_number, int north_or_south_field_number, const SENTENCE& sentence )
{
   // Thanks go to Eric Parsonage ([e-mail]) for finding a nasty
   // little bug that used to live here.

   double position = 0.0;

   position = sentence.Double( position_field_number );

   CString north_or_south;

   north_or_south = sentence.Field( north_or_south_field_number );

   Set( position, north_or_south );
}

void LATITUDE::Set( double position, const char *north_or_south )
{
   ASSERT( north_or_south != NULL );

   Latitude   = position;
   Coordinate = position;
   
   if ( north_or_south[ 0 ] == 'N' )
   {
      Northing = North;
   }
   else if ( north_or_south[ 0 ] == 'S' )
   {
      Northing = South;
   }
   else
   {
      Northing = NS_Unknown;
   }
}

void LATITUDE::Write( SENTENCE& sentence )
{
   char temp_string[ 80 ];

   ::sprintf( temp_string, "%07.2f", Latitude );
   sentence += temp_string;
   
   if ( Northing == North )
   {
      sentence += "N";
   }
   else if ( Northing == South )
   {
      sentence += "S";
   }
   else
   {
      /*
      ** Thanks to Jan-Erik Eriksson ([e-mail]) for
      ** finding and fixing a bug here
      */

      sentence += "";
   }
}

const LATITUDE& LATITUDE::operator = ( const LATITUDE& source )
{
   Latitude = source.Latitude;
   Northing = source.Northing;

   return( *this );
}

// COORDINATE stuff

// Coordinates are in the format dddmm.ddd
// For example, 76 degrees 46.887 minutes would be 7646.887

double COORDINATE::GetDecimalDegrees( void ) const
{
   double return_value = 0.0;

   int degrees = (int) ::floor( Coordinate );
   int minutes = degrees % 100;

   double fractional_minutes = 0.0;
   double throw_away         = 0.0;

   fractional_minutes = ::modf( Coordinate, &throw_away );

   degrees -= minutes;
   degrees /= 100;

   return_value = degrees;
   return_value += (double) ( (double) minutes / (double) 60.0 );
   return_value += (double) ( (double) fractional_minutes / (double) 60.0 );

   return( return_value );
}

double COORDINATE::GetDecimalMinutes( void ) const
{
   double return_value = 0.0;

   int degrees = (int) ::floor( Coordinate );
   int minutes = degrees % 100;

   double fractional_minutes = 0.0;
   double throw_away         = 0.0;

   fractional_minutes = ::modf( Coordinate, &throw_away );

   return_value  = (double) ( (double) minutes );
   return_value += fractional_minutes;

   return( return_value );
}

double COORDINATE::GetDecimalSeconds( void ) const
{
   double return_value = 0.0;

   double minutes = GetDecimalMinutes();

   double fractional_minutes = 0.0;
   double throw_away         = 0.0;

   fractional_minutes = ::modf( minutes, &throw_away );

   return_value = (double) ( (double) fractional_minutes * (double) 60.0 );

   return( return_value );
}

int COORDINATE::GetWholeDegrees( void ) const
{
   return( (int) ::floor( GetDecimalDegrees() ) );
}

int COORDINATE::GetWholeMinutes( void ) const
{
   return( (int) ::floor( GetDecimalMinutes() ) );
}

int COORDINATE::GetWholeSeconds( void ) const
{
   return( (int) ::floor( GetDecimalSeconds() ) );
}